In the hotmix asphalt industry, the hotmix prepared in an asphalt production plant is either discharged directly into waiting dump trucks for transport to a highway construction site, or is temporarily stored in auxiliary surge storage bins from which the hotmix may be intermittently dispensed to the dump trucks. In order to minimize trucking expense, the asphalt production plant is commonly located near the construction site. However, it is frequently necessary to move the plant as one project is finished and a new one is begun, and it is therefore desirable for the plant to be easily portable for transport between different job sites. Consequently, production plants have been developed which may be dismantled, transported to a new job site, and reassembled, all without the aid of cranes or other heavy construction equipment foreign to the ordinary operation of an asphalt plant.
The development of portable asphalt plants has left the auxiliary surge storage bins and their associated conveyors for elevating the hotmix from the plant to the top of the bins as the only equipment requiring the use of a crane for erection and dismantling. Due to the tremendous size and weight of the bins and conveyors required to store large volumes of asphalt, the various attempts heretofore made to provide self-erecting storage bins have suffered from numerous shortcomings.
One self-erecting silo assembly that has been developed is disclosed in U.S. Pat. No. 3,586,181, issued to James D. Brock and entitled "Portable Self-Erecting Silo". The silo assembly of Brock basically employs an upright bin structure having telescoping cylindrical walls which may be upwardly extended. The complex erection method, however, is somewhat cumbersome, including a number of motor reversals and various manual connections and disconnections. Furthermore, in the retracted or collapsed transport position, the Brock silo presents a profile as tall as the upper cylindrical section, which is approximately half the total height of the erect silo. The upper portion of the silo, therefore, is necessarily restricted in height so that the silo can pass beneath bridges and overpasses when transported on the highway. Such a height limitation runs contrary to the goal of providing a tall, large volume storage bin.
Accordingly, a need exists in the asphalt industry for a self-erecting surge storage system to temporarily store large volumes of hotmix and to be easily transportable between job sites and quickly erected without the aid of a crane or the like. The primary goal of this invention is to meet this need.
More specifically, an object of this invention is to provide a self-erecting surge storage system, including a large volume bin and associated conveyor, that can be quickly and easily raised from a travel position to an upright operational position and that can be readily lowered from the upright position to the travel position.
Another object of the invention is to provide a self-erecting surge storage system which may be easily and quickly raised or lowered to and from an upright operational position without the aid of a crane or other special equipment normally absent in the day-to-day operations of an asphalt plant.
Another object of the invention is to provide a self-erecting surge storage system of the character described which may be raised or lowered in safety to the construction personnel with the entire erection procedure controlled by a single operator remote from the structure itself.
Yet another object of the invention is to provide a surge storage bin which may be rotatably raised from a horizontal transport position to a vertically upright, operational position without the aid of a crane or the like.
An additional object of the invention is to provide a conveyor for a self-erecting surge storage bin which may be raised from a horizontal transport position to an inclined operational position without the aid of a crane or the like. Such positioning of the conveyor is accomplished simultaneously with the erection of the storage bin in order to minimize the assembly time.
Another object of the invention is to provide a self-erecting surge storage system of the character described which is readily transportable from one job site to another.
A further object of the invention is to provide a self-erecting surge storage system of the character described which presents a low profile when transported between job sites.
Still a further object of the invention is to provide a method of erecting a substantially conventional surge storage bin and conveyor from a travel position to an operational position without the aid of a crane or the like.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.